The renegade street artist painted the silhouette of a young boy swinging a sledge hammer, according to a picture posted to his web site Sunday morning. The work is strategically done next to a red standpipe, creating an illusion that the boy is going to smash it.

The mysterious British street painter is 20 days into his month-long project, captivating New Yorkers, eager to find where his next work will pop up.